Starting and operating circuit for electric discharge devices



Feb. 22, 1949. w. F. HODGE 2,462,320

STARTING ANDQPERATING CIRCUIT FOR ELECTRIC DISCHARGE DEVICES Filed Dec. 7, 1945 FIG. 2

20 BIMETAL MIL/q 27 1 I f/ CONTACTS NORMALLV CLOSED INVENTOR:

WILLIAM F. H00 5,

Patented Feb. 22, 1949 STARTING AN DTOPERA'IIING CIRCUIT FOR ELECTRIC DISCHARGE "DEVICES William- F. Hodge, ,Lyndhurst, .zoliio, assignor to General Electric Company, :a corporation of New York Application-December 7,1945, Serial N0.'fi33;'382

'5 Claims. 1 a My invention relates to-starting and operating arrangements for gaseous electric discharge. devices.

Anobject of this invention is to provide a .cir-

cuit arrangement whereby a pair of discharge.

devices may be started with but one starting device. Other objects and advantages of :my invention will appear from the following description .of species thereof.

The drawing is a diagrammatic representation t t aicircuit arrangement comprising :my invenion.

The circuit illustrated embodies :two :ga'seous electric discharge devices .I and 2 which "may be positive column discharge lamp devices comprising elongated tubular envelopes or containers 3 and 4 having sealed into the ends thereof the thermionic electrodes 5, -6, I and 8 each herein illustrated as consisting of a coil (preferablya coiled-coil of wire such as tungsten coated witha material .of high electron emissivity, such as an alkaline earth oxide like barium or strontium oxide or mixtures thereof). The envelopes 3 and. 4 contain a gaseous atmosphere such .asa rare gas like krypton, neon, argon, or mixtures thereof or a vaporizable metal such asmercury, preferably a mixture .of a .gas andvaporizable metal. The devices I and .Zmay below pressure positive column lamps of thefluorescent type with the envelopes coated internally with.a.suitable phosphor which under the influence ..of .an electric discharge through, .for example, a .combination of a rare gas and the mercury vapor,

' produces fluorescence.

The devicesv I and, 2 arerespectively connected in series with suitable ballast .impedances which may consist of resistances, for example in the form of incandescent tungsten filamentlamps 9 and I B. or a singlelamp containingtwo filaments which act as the ballasts 9 and I0,.and inductance or choke coils I i and I2. The ballastsQ and II! are connected on opposite sides of the lamps I and 2 from the choke-coils II and I2. The devices I and 2 and their associated ballasts and choke coils are electrically connected in parallel with each other across a suitablesource of current or power I9, I9, which for example may be a 118 volt, 60 cycle source, the choke coils being connectedto opposite sides of the source I9, I9.

'The starting or heating circuit l3 embodies filamentary electrode 5 in series with a push button starting switch M, a vibrator switch I5 with coil l6 and contacts H, and filamentary electrode I. A capacitance 88 of 0.01 microfarad rating is preferably connecteddirectly across the 2 vibrator switch 11:5 .and the starting push .button switch M.

.-In :accordance, with my invention .one vibrator type starting device I5 and a push button-switch .I 4' is'usedtostart two discharge lamps. Tostart athe lamp-switch i23zis' first closed, .andxthen switch 1:4 is closed to complete a circuit from the power linel9 through the inductance I I, the lamp electrode iiof.dischanze device I, the push button :switchIA, the :normallyclosedcontacts i1 :and ,thez'coil ;lB ;of the vibrator switch I15, the -lamp lectrqdelof. discharge devicei, the inductance .:t2 ,-rand-the otherpower line l9. In other words thecathodes 6,1 and'choke coils II, It are all connected in series across the power-source. The currentrlowin circuit i3pre-heats filaments fi :and 1, and opens contacts I1 by means of the magnetic fiuxof coil IB of the vibrator switch I5. When .the circuit is thus interruptecta very-high voltage klckisobtained from theind-uctances II and I2 and applied across the lampelectrodes :5,6 .and .1, 8 of discharge devices I.and.2 respectively. Inasmuch as the magnetic switch operatesion eachhalf cycle of current a series of 2 ;voltage.kicks Willbe applied to thelainp. 'Starting.is.substantially instantaneous for all practi- --.cal purposes. Ifthe lamp fails to light, aseries pf voltage i-kicks is obtained-from the vibrator action .or ,themagnetic switch I5 asitopensand ,closes. Thehigh voltageimpulses are repeated .in vvery rapidsuccession so that the ionization .pro'ducedin thejlamp by the first voltage impulse is continued :and'is built. up or reinforced by the second voltage impulse and also thethird and so .on until the lamp lights. After both lamps I and '2';have started the push button switch is released to open circuitposition. I

"The discharge devices may for example be 32 watt circular fluorescent tubes of 12 inch diam- ,-eter containing a gaseous atmosphere ot-argon Alternatively, :one of the discharge devices may "be 2,3'watt:circular fluorescent tube of 8 inch diameter containing a gaseous atmosphere or argon and 'vaporizable mercury with a voltage drop of 59 volts at approximatelyOAZ ampere. The'ballast lamp. and choke ,coil in series therewith wouldbe rated-at 61 volts,- 0;4-2 "ampereand 35 millihenries, respectively. If desired, the ballast lamps 9 and I0 may be omitted and the inductive reactance of choke coils II and I2 in- 65 creased to ballast the lamps.

If desired, pre-heating of the electrodes 6 and 1 may be dispensed with. In this case the starting circuit 13 is connected at one end between the lamp I and the inductance H, and at the other end between lamp 2 and the inductance [2.

The vibrator switch l may be a normally closed but quick opening electromagnetic switch calibrated to open only on the A.C. voltage peak. As shown in Fig. 2 the switch is preferably of the vacuum type comprising a tubular envelope 20 with leads 21 and 22 sealed in one end of the envelope 20 and consisting of any suitable material for example a nickel lead 2| and a tungsten lead 22 with the former acting as the stationary component of the switch and the latter the spring component of the switch. A pair of soft iron' discs 23 carrying tungsten contacts 24- mounted perpendicular to each other are fastened by suitable means to the ends of leads H and 22. Although the contacts 24 are, normally closed they are shown in Fig. 2 in their open position for the sake of clearness. The coil 25 may for example be eight hundred turns of number 32 copper wire.

The push button starting switch may be replaced by a glow switch [4' indicated in Fig. 2. A species of this type of switch is disclosed in the United States Patent No. 2,329,134 issued September 7, 1943 to L. R. Peters. The glow switch ll comprises a hermetically sealed glassenvelope 26, a U-shaped electrode 21 comprising a thermally responsive bimetallic element welded to support 28, an electrode 29 comprising a metal rod such as nickel, and an ionizable gaseous atmosphere therein such as argon at a pressure of about 25 mm., helium at a pressure of about 100 mm., or a'mixture of helium and 0.01 to 5 per cent argon at a pressure of about 100 mm.

The feature of employing a serially connected glow switch having normally open contacts and a magnetic vibrator having normally closed contacts for impressing a series of impulses of starting voltages across the electrodes of an electric discharge device for a predetermined period of time established by the closure of the glow switch contacts is disclosed and claimed in co-pending' patent application Serial No. 616,904 of Royal F. Strickland filed September 17, 1945, and which is assigned to the assignee'of this application.

With the arrangement shown in Fig. 2, when potential is applied to the circuit by closing the main line switch 28 (Fig. 1) the glow discharge starts in the glow switch, the gap between the switch electrodes is closed by the flexing of the bimetallic electrode to extinguish said glow dis-- What I claim as new and desire to secure by 7 Letters Patent of the United States is:

1. In combination, a pair of gaseous electric discharge devices each comprising a sealed envelope containing spaced electrodes, means connecting said discharge devices in parallel across a source of power with an inductance in series with each discharge device, said inductances being connected to opposite sides of said source of power, and a starting circuit including switch means connecting said inductances in series across said source of power for starting said devices.

2. In combination, a pair of gaseous electric discharge devices each having a thermionic cathode and a cooperating electrode, means to connect said discharge devices in parallel across a source of power with an inductance in series with each device, and a heating circuit including starting switch means connecting a cathode of one device with the cathode of the other device in series and in series with the said inductances across said source of power.

3. In combination, a pair of gaseous electric discharge devices each having a thermionic cathode and a cooperating electrode, means to connect said discharge devices in parallel across a source of power with an inductance in series with each device, and a heating circuit including starting switch means connecting a cathode of one device with the cathode of the other device in series and in series with the said inductances across said source of power, said starting switch means including a magnetic vibrator switch having normally closed contacts and a second switch in series therewith and capable of maintaining the heating circuit closed until both lamps start.

4. In combination, a pair of gaseous electric discharge devices each having a thermionic cathode and a cooperating electrode, means to connect said discharge devices in parallel across a source of power with an inductance in series with each device, and a heating circuit including starting switch means connecting a cathode of one device with the cathode of the other device in series and in series with the said. inductances across said source of power, said starting switch means including a magnetic vibrator switch having normally closed contacts and a manual switch in series therewith.

5. In combination, a pair of gaseous electric discharge devices each comprising a sealed envelope containing spaced electrodes, means connecting said discharge devices in parallel across a source of power with an inductance and a resistive ballast in series with each discharge device and on opposite sides of said device, said inductances being connected to opposite sides of said source of power, and a starting circuit including switch means connecting said inductances in series across said source of power for starting said devices.

WILLIAM F. HODGE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

